Replication of GWAS-identified systemic lupus erythematosus susceptibility genes affirms B-cell receptor pathway signalling and strengthens the role of IRF5 in disease susceptibility in a Northern European population

Rheumatology (Oxford). 2012 Jan;51(1):87-92. doi: 10.1093/rheumatology/ker263. Epub 2011 Oct 27.

Abstract

Objective: A large number of genes, including several not previously implicated in SLE susceptibility, have recently been identified or confirmed by genome-wide association studies (GWAS). In this study, we sought to replicate some of these results in Finnish SLE patients (n = 275) and control individuals (n = 356).

Methods: We genotyped 32 single nucleotide polymorphisms (SNPs) in 12 of the best-supported GWAS-identified SLE genes and loci. We further investigated gene-gene interactions between the loci included in the study.

Results: The strongest evidence of association was found at the IRF5-TNPO3 locus, with the most significant P-value being 2.0 × 10(-7) and an odds ratio of 1.95 (95% CI 1.51, 2.50). Association between SLE and TNFAIP3, FAM167A-BLK, BANK1 and KIAA1542 was also confirmed, although at a lower significance level and contribution to individual risk. No significant association was found with 1q25.1, PXK, ATG5, ICA1, XKR6, LYN and SCUBE1. Furthermore, no significant gene-gene interactions were detected.

Conclusion: Replication of previous GWAS findings across diverse populations is of importance to validate these associations and to get a better understanding of potential genetic heterogeneity between populations in SLE susceptibility. Our results attest the importance of B-cell receptor pathway and IFN signalling in SLE pathogenesis.

Publication types

  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Case-Control Studies
  • Epistasis, Genetic / genetics
  • Genetic Predisposition to Disease
  • Genome-Wide Association Study
  • Genotype
  • Humans
  • Interferon Regulatory Factors / genetics*
  • Linkage Disequilibrium
  • Lupus Erythematosus, Systemic / genetics*
  • Lupus Erythematosus, Systemic / immunology
  • Polymorphism, Single Nucleotide
  • Receptors, Antigen, B-Cell / physiology*
  • Signal Transduction / genetics

Substances

  • IRF5 protein, human
  • Interferon Regulatory Factors
  • Receptors, Antigen, B-Cell